Steam-engine governor



No Model.)

H. G. SMITH. STEAM ENGINE GOVERNOR.

.No. 530,970. Patented Dec. 18, 1894.

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HORATIO G. SMITH, OF FITOHBURG, MASSACHUSETTS.

STEAM-ENGINE GOVERNOR.

SPECIFICATION forming part of Letters Patent No. 530,970, dated December18, 1894.

Application filed February 28, 1894. Serial No. 501,863- (No model.)

To all whom it may concern.-

Be it known that I, HORATIO G. SMITH, of Fitchburg, in the county of\Vorcester and State of Massachusetts, have invented certain new anduseful Improvements in Steam- Engine Governors; and I do hereby declarethe following to be a full, clear, and exact description of the same,reference being hadto the accompanying drawings, forming a part of thisspecification, and to the letters of reference marked thereon.

This invention relates to improvements in governors, such as haveweighted pendulous arms (conical pendulum) swung outward by centrifugalforce to move or control the movements of the valve, its connections orequivalent direct controlling mechanism forthe engine or machine.

As is we1l.known, a weight resistance has been used to increase thevertical height of the cone and thereby greatly increase thesensitiveness of the governor, such weight usually being applied soas todirectly resist the outward swing of the pendulous arms. The pendulousweighted arms exert a maximum effective power when hanging in planesnearest to parallel with the axis of rotation of their support or whenthe vertical height of the cone formed thereby is greatest, and aconstantly diminishing effective power as they swing out into planesnearer at right angles to said center of rotation and the verticalheight of the cone is reduced. Hence as the resistance to be overcomethereby is constant, a greater percentage of the relative and constantlydiminishing effective power exerted by the pendulous arms, is expendedin overcoming it. Consequently the speed with which the arms move undervariations in the speed, of the engine diminishes when moving in bothdirections from the angle assumed at normal speed, and the sensitivenessof the governor diminishes.

It is the object of my invention to overcome this difiiculty and byreducing the effect or leverage of the-weight resistance in proportionas the pendulous arms swing out and their power diminishes and byincreasing the leverage as the arms swing in, cause them to move with anincreasing velocity in each direction, thereby making the governor muchmore sensitive to variations in the speed of the engine or machine thanthe old form of governor.

Referring to the accompanying drawings: Figure 1 is an elevation of agovernor constructed in accordance with my present invention. Fig. 2 isa section through the same. Fig. 3 is an elevation at right angles toFig.

'2. Fig. 4 is a diagrammatic view illustrating the action of the arms inovercoming the resistance of the weight.

Similar letters of reference in the several figures indicate the sameparts.

The letter A indicates the stand or standard upon which therevolvingparts are supported; B, the hollow shaft passing through the standardand forming the connection between the rotary head 0 and some movingpart ofthe engine or machine. The pendulous weighted arms D arepivotally connected to and supported by the head 0 to swing out and intoward the center on which the head rotates, and in the preferredconstruction, are connected with the valve or its connections by shorterarms 0 jointed to'a valve rod E in any ordinary or preferred manner soas to move said rod as the pendulous arms move out or in.

Head 0 it will be understood is suitably journaled on the stand orstandard and connected rigidly with the shaft B, although these partsmay be of any ordinary or preferred construction adapted for the use ofa weight to return the valve rod to first position and form theresistance to the tendency of the pendulous arms to stand at rightangles to the center of rotation when the engine is running. As shown,this weight lettered F surrounds the top of the standard and base of thehead, so as to be capable of rotation thereon and also of movingvertically to a limited extent.

The connection between the weight F and pendulous arm is made asfollows: Each armis provided with an upward extension or projection orsupplemental arm projecting at such an angle that when the pendulousarms move out, the supplemental arms will move nearer to a verticalposition with relation to the centers on which the arms swing, and linksH connect the outer ends of the upward extensions or supplemental armsand weight, the etfect of which construction is to reduce the leverageexerted by the supplemental arms as the pendulous arms swing out, andthe points of attachment of the weight supports move more nearly overthe centers.

The arms are so proportioned, and the relative angles of the points ofattachment of the weight support and centers on which the arms pivot areso arranged, that, as the effective power of the pendulous armsdecreases the leverage of the supplemental arms decreases, allowing thearms to move with an increasing velocity, and in moving inward becauseof diminishing speed, the leverage of the weight increases causing thearms to swing inward with an increasing velocity. This constructionmakes the governor much more sensitive and secures a quicker action thanheretofore.

By the term effective power used herein, I mean the power exerted by thependulous arms which can be utilized. for moving the valve connections.

I am aware that lever arms with diminishing effective power have beenemployed to equalize the pressure of springs employed as the resistanceto the outward swing of the weighted pendulous arms, but the effect insuch structures is only to secure the same sensitiveness that the devicewould possess if weights instead of springs had been employed.

I am also aware that the diminishing effective power of the weightedpendulous arms has been compensated for when a weight formed theresistance, but the mechanisms for accomplishing this result have beencomplicated and of such nature as to prevent their practical use.

Having thus described my invention, what I claim as new is- In agovernor, the combination with the standard, the rotary head carriedthereby, the central shaft for rotating said head, the valve rod and theexternal independently movable weight, of the pendulous weighted arms,pivoted in the head and each having a short supplemental arm 0 pivotallyconnected with the valve rod and a relatively long arm C projectingoutwardly and upwardly at such an angle as to be at its leastinclination when the pendulous arm is close to the standard and to standin its most nearly vertical position when the pendulous arm is at theoutward limit of its movement, and links pivotally connected to the arms0 at the upper end and pivotal connections between the links and Weight;substantially as described.

HORATIO G. SMITH.

Witnesses:

LEONARD 0. KING, SEWALL FOSTER.

